<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<script src="../../js/jquery-3.7.1.js" type="text/javascript" charset="utf-8"></script>
		<script type="text/javascript">
			$(function(){
			$("#num2").bind("change",function(){
				let n1=$("#num1").val()-0
				let n2=$("#num2").prop("value")-0
				let sum=n1+n2
				$(":disabled").val(sum.toFixed(16)-0)
			})	
				
			})
		</script>
	</head>
	<body>
		<input type="text" id="num1" placeholder="第一个数">+
		<input type="text" id="num2" placeholder="第二个数">=
		<input type="text" id="num3" placeholder="计算结果" disabled="disabled">
	</body>
</html>
